1. Field
At least one example embodiment relates to a reinforced composite membrane and a method of manufacturing the reinforced composite membrane.
2. Description of Related Art
One of key parts that constitute a fuel cell is a polymer electrolyte membrane (PEM). This PEM is a part to perform actual hydrogen ion conduction in the fuel cell, and is also a very important part to determine the performance of the fuel cell and the economical efficiency.
A perfluorinated electrolyte membrane currently in commercialization has some advantages, such as an excellent mechanical strength and electrochemical characteristic, and also has some disadvantages, such as relatively high cost by a complex production process and a relatively low glass transition temperature by a fluorinated structure. To overcome the disadvantages, the development of hydrocarbon polymer has been actively conducted. In addition, the development of a hydrocarbon based membrane has been reported, which may be manufactured at relatively low cost and thermally further stable compared to a perfluorinated polymer electrolyte membrane. However, due to a wet/dry cycle during an operation of the fuel cell, the mechanical strength of a membrane may become weak, which may result in causing a fracture or a crack in the membrane.
Currently, a reinforced composite membrane in which a thermally and mechanically stable porous reinforced support is impregnated with an electrolyte has been developed. A brushing or impregnation process by vacuum is performed a plurality of number of times to impregnate a porous reinforced support with an electrolyte. Alternatively, a method of employing a surfactant is applied to enhance an interfacial adhesive force between a hydrophobic porous reinforced support and an electrolyte. In the case of using such existing impregnation methods, a large scale manufacture is difficult and a relatively long process time is required. Further, damage to a reinforced support frequently occurs and uniform electrolyte impregnation is difficult. Also, since an interfacial adhesion between an electrolyte and a support varies based on a type of the support, it is difficult to adjust an interfacial adhesive force. In particular, a reinforced composite membrane currently applicable to a vehicle uses a very thin membrane with a thickness of 20 μm or less to enhance the performance of a fuel cell. An existing method has some constraints in thinness due to an electrolyte remaining on the surface.